Techniques of Discovering hazards and Risk Mitigation

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Hazard management in Power Sector:
Techniques for Hazard Identification &
Risk Mitigation
By
Dr. Rohit Verma Dy.Director NPTI
Dr. Manisha Rani Fellow,NPTI
DEFINATIONS
HAZARD
Source or situation with a potential for harm in
term of injury or ill health, damage to property,
damage to workplace environment, or
combination of these.
HAZARD IDENTIFICATION
Process of recognizing that a hazard exists and
defining its characteristic
RISK
Combination of likelihood & consequences of a
specified hazardous event
RISK ASSESSMENT
Overall process of estimating the magnitude of
risk and deciding weather or not the risk is
tolerable
ACCIDENT
Unplanned & unexpected event which results
into injury or property damage is known as
accident.
CAUSES OF ACCIDENTS
 Unsafe
conditions
unsuitable clothing for a particular job
 untidy work area
 tools in poor condition
 poor lighting in work area

 Unsafe
act
using equipment without having received proper
training in its use
 failing to use the appropriate protective
equipment
 distracting others from their work or allowing
yourself to be distracted
 using tools or equipment incorrectly.

TYPES OF OCCUPATIONAL HAZARDS
·
Physical hazards
·
Chemical hazards
·
Biological hazards
·
Mechanical / Electrical hazards
·
Psychosocial hazards
TYPES OF OCCUPATIONAL HAZARDS
Physical






hazards
Heat
Cold
Light
Vibration
Radiation
Noise
Chemical
Biological
Mechanical-electrical
Psychological
PHYSICAL HAZARDS
HEAT
The direct effects of heat exposure are
•
•
•
Heat exhaustion heat stroke [civil works]
Burns [boiler area, electrical flash over]
Heat cramp [civil works, boiler area]
COLD
Important hazards associated with cold work
[[[[[[
•
•
•
•
Frost bite
Chilblains
Immersion foot
General hypothermia as a result of cutaneous
vasoconstriction
PHYSICAL HAZARDS
HEAT- As a hazard in power stations can cause
1.
Heat stress-it is the aggregate of environmental &
physical work factor i.e. Total heat imposed on the body.
2.
Heat strain- it is the physiological responses to the heat
stress.
3.
Heat disorders-these result in heat cramps, heat
exhaustion, heat stroke.
4.
Heat cramps: painful intermittent spasms of voluntary
muscles after hard physical work in hot environment.
Cramps usually occur after heavy sweating.
5.
Heat exhaustion: profuse sweating, weakness, rapid pulse,
dizziness, nausea & headache. Skin is cool/pale. Body
temperature is normal, nausea, vomiting and
unconsciousness may occur.
Physical Hazards
Light as a hazard in working condition can be due
to:


Less lighted areas
when the light is insufficient person strains
his eyes to see the work object/area. Light
requirements are increasing with age of a
person to see and work on the object.
Excessive lightit is dangerous for eyes when light in work
area is excessive since it causes glare.
Physical Hazards
LIGHT
Effect of poor illuminations are :• Headache
• Eye pain
• Lachrymation
• Congestion around the cornea
• Eye strain
• Eye fatigue
Exposure to excessive brightness is associated with
discomfort, visual fatigue, blurring of vision and may lead
to accidents.
Physical Hazards
VIBRATION
VIBRATION
ESPECIALLY
IN
THE
FREQUENCY OF 10 TO 500 HZ, CAN
AFFECT HAND AND ARM AFTER MONTH
OF YEARS OF EXPOSURE
Ill effects:
•
The fine blood vessel of finger becomes
sensitive to spasm (white fingers).
increasingly
•
Injuries of the joints, of the hands elbow and shoulders
may take place
Physical Hazards
NOISE
•
Industrial noise can give rise to deafness
•
Non auditory effects are irritation, nervousness,
annoyance, fatigue, inefficiency etc.
Hearing impairment due to Noise is, as per the
schedule of the Factories act, is reportable as well as
compensable.
 Hearing loss in most cases is not sudden but increases
with the length of the work time in the noisy zone.

Physical Hazards
NOISE
Threshold Limit Value for noisy working conditions:
(An 8 hour shift in all following cases)







8 hours work – 90 dBA
4 hours working – 95 dBA
2 hours working – 100 dBA
1 hour working – 105 dBA
half hour work – 110 dBA
Threshold of hearing – 125 dBA
Sudden deafness/rupture of ear drum can occur at 140 dBA
Physical Hazards
RADIATION
A. ULTRAVIOLET
RADIATION HAZARD-
SEEN IN WORK WITH ARC WELDING AND MAINLY
AFFECTS
THE EYES.
EXPOSURE TO SUCH RADIATION MAY LEAD TO
CONJUNCTIVITIS AND KERATITIS (WELDER’ S FLASH)
B. IONIZING RADIATION HAZARDS[X ROOM USG CT]
ANEMIA
LEUKEMIA
CANCER
STERILITY
FETAL MALFORMATION IN CASE OF PREGNANCY
ULCERATION
IN EXTREME CASES DEATH CAN TAKE PLACE
MECHANICAL / ELECTRICAL HAZARDS

Accident

Fall

Injury

Electricity burn

Electric shock.
ELECTRICAL HAZARDS
Injury from direct contact
1.
Injury by shock
2.
Injury from internal burns
Injury without current flow through body
1.
Direct burns from electrical arcs
2.
Radiation burns from very heavy arcs
3.
Injury from fire & explosion from electrical arc
4.
Physical injury from false starting of machinery, failure of
controls
5.
Eye injury from electrical arc welding
CHEMICAL HAZARDS
Chemical hazards – liquid and gaseous hazards
1.
Dust
2.
Smoke
3.
Fumes
4.
Poisonous gases
5.
Acids
6.
Alkalis
CHEMICAL HAZARDS
They enter our body through

Skin

Inhalation

Mouth
They can cause internal as well external injuries

Skin diseases

Lung diseases

Internal blood and other diseases
BIOLOGICAL HAZARDS
Exposure to infective and parasitic agents
• Inset bite
 Dog bite
 Snake bite
•
PSYCHOSOCIAL HAZARDS
FACTORS • Maladjustment
with
work
environment.
• Lack of job satisfaction
• Insecurity
• Emotional tension
• Poor human relationships
Health problems
Behaviors changes
•Anxiety/Depression
•Sickness absentees
Fatigue
Headache
Hypertension
Heart disease
Peptic ulcer
PREVENTION
MECHANICAL HAZARD
PREVENTION
•
•
•
•
•
•
Preventive maintenance
Adequate job training
Ensuring safe working
environments
Establishment of safety
department with qualified
safety engineer
Periodic survey for finding out
hazards
Application of ergonomics
Physical Hazards
NOISE
Noise can be controlled by;
1.
Reducing vibrations
2.
Enclosing the noise
producing equipment
3.
Enclosing the operator
4.
Moving away from the
noisy area
5.
Use of personal protective
equipments
Physical Hazards
Effective temperature and
heat effect in an environment
can be controlled by:
 Increasing
air changes
 Reducing radiated heat by
insulation
 Reflection of heat
 Drinking plenty of water and
intake of salt
 Use of personal protective
equipments
Physical Hazards
VIBRATION
Continuous
working should be avoided and rest pauses
after some time of work must be allowed to workers.
The
by;



1. Reducing the forces
2. Minimizing rotational speed
3. Isolating
The




driving force of vibrating surfaces may be reduced
response of vibrating surfaces may be reduced by
1. Damping
2. Additional
3. Increasing mass of vibrating surfaces
4. Changing size to change resonance frequency
MECHANICAL HAZARDS
MACINERY HAZARDS:
 These are due to revolving parts of the machines.
 These can be controlled by providing machine guards which
are a statutory requirements under Sections 21 to 26 of the
Factories Act 1948.
 As per section 21 of the Factories Act- provide guards at
following;
 Moving parts of the machinery including fly wheels
 Transmission machinery
 Point of operation
 Any other dangerous part
Mechanical Hazards
SAFETY OF MAINTENANCE PERSONNEL
 Safety
precautions are required to safe guard
the maintenance personnel from getting
involved in machinery accidents owing to
inadvertent starting of machinery by;
Design of control switches
Safe guards for the operating levers
Interlocking of power system
PREVENTION
Physical hazards
•
•
•
•
•
•
•
•
•
•
Application of ergonomics
Maintenance of temperature- 69 to 80 deg. F is the comfortable
zone
Proper ventilation
Good housekeeping
Proper illumination
Personal protection
Personal hygiene
Health education
Job rotation
Periodic health Check up
Biological Hazards
PREVENTION
•
•
Personal Protection
Post Control
Psychosocial Hazards
PREVENTION
• Good induction program.
• Management by participation.
• Establishment of Proper communication
channel.
• Establishment of Healthy personnel
policies
• Establishment of healthy HR relationship.
• Regular stress management program.
CHEMICAL HAZARDS
Chemical Safety

There are thousnands of chemical compounds,
which presents some form of hazards either major
or minor incidents usually termed as chemical
accidents.

To avoid chemical accidents some points to be kept
in mind.
1.
knowledge of chemicals
2.
knowledge of pocessing plant
3.
knowledge of operator
CHEMICAL HAZARDS IN POWER
PLANT

Coal/silica dust is major health hazard in power station

These dusts enter our body through inhalation




Respirable dust particles can enter our lung sacks and
reduce our breathing capacity since this reparable dust
settles there,
Normally coal dust particle less than 1 micron only can
enter in our lung sacks.
Bigger dust particles either remain in our nose or get stuck
in throat. Then they go into stomach and get removed from
our body system in natural way.
Coal dust is non toxic and as such no effects are caused on
body due to the particles of dust in stomach.
CHEMICAL HAZARDS




Respirable dust particle which enter into our lungs can
not be removed and they remain settled there.
Disease which can occur due to inhalation of coal dust
is known as “pneumoconiosis” and is irreversible till
person is shifted from job
Silica dust can cause “silicosis”
Both are reportable as well as compensable diseases
under the schedule of the factories act
CHEMICAL HAZARDS
Control of coal dust by




Reduction of dust emission by suppression by
wetting coal in wagons, at the time of tippling, water
spray in coal conveyors.
Suction of coal dust from environment in above
areas.
Use of personal protective equipments like filter
respirators which can filter out reparable coal dust
particles.
Continuous monitoring of environment by
measuring and keeping it below.
2. Gases
Chemical Hazards
Gases are the common hazards in many industries leads to
suffocation and asphyxia.
Asphyxiating gases are – CO, Cyanide, SO2, Chlorine etc.
Smoke: inhalation of smoke which can contain poisonous
gaseous fumes also and can have effects on our health;
Fumes: fumes emanating from liquid chemicals can cause ill
effects on our health when inhaled;
Vapor: vapors of chemicals liquids are also dangerous to our
health when inhaled. Vapours of hydrazine hydrate can cause
unconsciousness when inhaled.
Chemical Hazards
3.Metals and compounds
Toxic hazards are seen from Lead, Mercury, Chromium, Arsenic etc
4.Chemicals
Acid (water treatment/ chemistry), Alkali and Pesticides.

Hazardous chemicals used in thermal power stations:
 Chlorine
 Hydrochloric acid
 Euphoric acid
 Hydrazine hydrate
 Liquor ammonia
 Sodium hydroxide
CHEMICAL HAZARDS
Chlorine

It is the most hazardous chemical used
It is used in water treatment plant
 It is procured in toners for use in chlorinationation
 When more than 10 tons of chlorine is stored/
handled/used in any industry, a Disaster Management
Plan (DMP) is required to be prepared and submitted to
statutory authorities.
 This DMP is required to be practiced through mock drills
periodically and review meeting are to be conducted for
checking discrepancies.

CHEMICAL HAZARDS
Chlorine
Chlorine vapor is poisonous when inhaled
 Will cause burn in eyes
 Chlorine liquid can cause burn on skin and eyes
 Threshold Limit Value (TLV) for chlorine is 1 ppm
 At 100 ppm it can be fatal.

PLANT / SECTIONS WHICH ARE PRONE TO
EMERGENCIES
1.
2.
3.
4.
5.
Coal handling plant
Main plant
Water treatment
plant
Hydrogen
generation plant
Mgr transpiration
system
PREVENTION OF CHEMICAL HAZARD (PNEUMOCONIOSIS)
1.Dust control· Proper Ventilation
· Exhaust
· Enclosed apparatus
· Good house keeping
2.Personnel protection
· Mask, clothing, cloves, apron, boots barrier cream etc
3.Personal hygiene
4.Health education about respiratory evolvement
and personal protection
5.Medical control
Periodic medical check up for early detection
6. Bagasse control· Spraying with 2% propionic acid· Keep the moisture content around 20%
Fire hazard
Fire is a chemical reaction or series of
chemical reaction accomplished by heat,
light, smoke or other gases.
FIRE HAZARDS IN POWER PLANTS
 Coal
handling plant:
coal dust accumulation on conveyor decks,
cable trays, head & tail pulleys, jamming of
idlers and pulleys, belt sway, belt tension, dust
& coal deposited at tops, crusher house and
vibrating scene floors, bunker house , failure of
belt joints, snapping of belts, partially
damaged belt in operation, smoldering fire in
bunkers
FIRE HAZARDS IN POWER PLANTS
 Cables
in cable galleries and on trays in all plant
sections, coal dust deposited on cable trays in
mill area
 Fuel oil handling and oil tanks (hsd,hfo,lshs,
naphtha, petrol, diesel oil )
 Transformer oil, turbine oil, control fluid, seal oil,
 Natural gas
 Electrical system
 Heat path damaged insulation
 Grass
 Accumulation of waste material etc.
EXPLOSION HAZARD IN POWER PLANT
Hydrogen plant
 Turbo generators where hydrogen is
used for cooling of Generator.
 Boilers

How to
Control
Hazard ?
3 step
process
Step 1: Hazard Identification Techniques
Hazard Identification Techniques
• Safety audit
• Safety survey
• Safety inspection
• Safety tour
• Safety sampling
• Job safety analysis
• Hazard & operability studies
• Fault & event tree analysis
• Failure mode & effect analysis (FMEA)
50
Hazard Identification Techniques
Safety audit
A systematic & independent examination of all or
part of a total operating system to determine
whether safety activities comply with planned
arrangements for ensuring safety and health of
workers and other interested parties who may be
affected and whether these arrangements are
effective and are suitable to achieve objectives.
Hazard Identification Techniques
Safety survey
Safety survey is a detailed & in-depth
examination of a narrow field of activity eg...
•Major key areas revealed by safety audit,
•Individual plants,
•Procedures or
•A specific problem.
Hazard Identification Techniques
Safety inspection
A
routine
scheduled
inspection
department or
unit
carried out
personnel
During
by
inspection
which
may
of
a
be
within the unit.
deviations
from
safety
standards, employee’s unsafe work practices
and unsafe conditions are checked.
Hazard Identification Techniques
Safety tour
Safety tour is an unscheduled examination of
a work area, carried out by any personnel
from manager to safety committee members
to ensure that company’s safety standards and
procedures are being observed.
Hazard Identification Techniques
Safety sampling
A specific application of safety inspection /
tour designed
for
random sampling of any
activity posing serious accident potential.
During safety sampling number of defects
Are
observing
actions.
for
immediate
corrective
Hazard Identification Techniques
Hazard and operability studies
Hazop is essentially a examination procedure
takes
full
systematically
description
questioning
of
the
of
every
process,
part
of
process to discover how deviations from the
intention of the design can occur and decides
whether these deviations can give rise to hazard.
Hazard Identification Techniques
Principles of examination
•Full description of the process, systematically
questions on every part of the process
•Discover deviations from the intention
of
the design can occur
•Decides weather these deviations
rise to Hazards
can
give
Failure Mode and Effect Analysis (FMEA)
• Failure or Malfunction of each component is
considered
• Effect or Consequences of failure traced
• Frequency of Occurrence, Severity of Failure and
detecting the problem
• Impact on the System Functioning is evaluated
• Remedial method for Possible Impact
Fault Tree Analysis
• Starts with Undesired event.
• All possible happenings contributing Undesired
event is listed.
• Put these happenings in the form of tree with
logic signals OR and AND.
JOB SAFTEY ANALYSIS (JSA)
•JSA is a procedure used to review job methods at the design stage
itself to ensure safe working at the site places and to adopt the safe
working practices.
• However, it may also be used successfully to uncover hazards that
may have developed after production started: or that resulted from
change in work procedures.
•The procedure of job safety analysis is simple and consists of 4
basic steps.
a) Jobs with potential for more frequent accidents,
b) Severity of injury
c) New jobs in which the accident potential is unknown should be
selected first from the entire job list.
d) Proper Care for analyzing the job condition.
PLANT SAFETY INSPECTION
Inspections are that monitoring function conducted in the
organization to locate and report existing and potential
hazards which have the capacity to cause accidents in the
work place.
Inspections are not primarily aimed at unearthing new types
of hazards; though that may be achieved also; but rather at
locating and correcting known hazards.
• Continuous Inspection
• Periodic Inspection:
Steps to Control
Hazard
Step 2. List, rank and set priorities
for hazardous jobs List jobs with hazards that present
unacceptable risks, based on those most
likely to occur and with the most severe
consequences. These jobs should be
your first priority for analysis.
Steps to Control
Hazard
Step 3. Controlling Hazards
Solutions to the Control of Hazard are identified
and measures are executed
Hazard can be eliminated
(i)
At the Source
(ii)
Along the path from hazard to the Worker
(iii)
At the level of the worker
Hazard Removal at the Source
1.Elimination - Getting rid of a hazardous job,
tool, process, machine or substance is
perhaps the best way of protecting workers.
2.Substitution - Sometimes doing the same
work in a less hazardous way is possible.
3.Redesign - Jobs and processes can be
reworked to make them safer.
4.Isolation - If a hazard cannot be eliminated
or replaced, it can sometimes be isolated,
contained or otherwise kept away from
workers.
5.Automation - Dangerous processes can be
automated or mechanized.
Hazard Removal
along the path from Hazard to
Worker
1. Barriers - A hazard can be blocked before it
reaches
workers.
Proper
equipment
guarding will
protect
workers
from
contacting moving parts.
2. Absorption - Baffles can block or absorb
noise.
3. Dilution - Some hazards can be diluted or
dissipated. For example, ventilation systems
can
dilute toxic gasses before they reach
operators.
Hazard Removal at the Level of Worker
 Work procedures, supervision and training
 Administrative controls
 Job rotations and other procedures can reduce
the time that workers are exposed to a hazard
 Housekeeping,
repair
and
maintenance
programs
 Hygiene - Hygiene practices can reduce the
risk of toxic materials being absorbed by
workers or carried home to their families.
 Personal protective equipment (PPE) and
clothing - This is used when other controls
aren’t feasible and where additional protection
is needed. Workers must be trained to use and
maintain their equipment properly.
RISK MANAGEMENT
 Risk
Management is the
Identification, Analysis and
Economic control of those risks
which can threaten the assets,
human being or earning capacity of
an enterprise
STAGES IN RISK MANAGEMENT
 Identifying
the hazards
 Evaluating the associated risks


The likely effect of a hazard may for Example be
rated: Major, Serious, SlightThe likelihood of harm may be rated: High,
Medium, Low
 Controlling
the risks
CONTROLLING RISK
Risk Avoidance
 Risk Retention
 Risk Transfer
 Risk Reduction

CONCLUSIONS
The thought process behind selecting hazard evaluation
techniques is complex, and a variety of factors can
influence the decision-making process.
 Hazards
identification, hazards categorization, and
hazards analysis are key components of integrated safety
management for facilities and activities in industries.
 Each hazard evaluation technique has unique strengths
and weaknesses.
 These techniques can provide the industrial hygienist with
the tools needed to protect both workers and the
community from both major and small-scale hazards.
 Probability of occurrence of hazard increases the risks
associated with an industry.
 A risk management proposal has been given for the ready
reference in this paper.

REFERENCE
•Ericson, C. (2005). Hazard analysis techniques for system safety. New York: John
Wiley and Sons.
•Leveson, N. (1995). Safeware: System safety and computers. Reading, MA:
Addison-Wesley.
•Mannan, S. (Ed.). (2005). Lees' loss prevention in the process industries.
Burlington, MA: Elsevier Butterworth-Heinemann.
•Manuele, F. (2008). Advanced safety management focusing on ZlO and serious
injury prevention. New York: John Wiley and Sons.
•Suokas, J. (1985, Sept.). On the reliability and validity of safety analysis [Technical
Report Publications 25]. Espoo, Finland: Technical Research Center of Finland.
•Suokas, J. (1988). Evaluation of the quality of safety and risk analysis in the
chemical industry. Risk Analysis, 8(4), 581-591.
•Suokas, J. & Kakko, R. (1989). On the problems and future of safety and risk
analysis. Journal of Hazardous Materials, 21, 105-124.
•Suokas, J. & Pyy, P. (1988). Evaluation of the validity of four hazard identification
methods with event descriptions [Research Reports 516]. Espoo, Finland: Technical
Research Center of Finland.
•Suokas, J. & Veikko, R. (1989, April). Quality control in safety and risk analysis.
Journal of Loss Prevention in Process Industry, 2, 67-77.
Thank You
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